Interaction with Grayscale and Gamma on a Panasonic PZ80U

I've recently done a grayscale calibration on my Panasonic PZ80U with an i1d2 and ColorHCFR. I have left green cut at the default 80 and green drive at the default (and max recommended) FC. My question is not about grayscale itself but rather how grayscale controls affect gamma.

I've discovered that keeping the picture setting low (30 ftL) produces higher gamma than when it is set higher. The same holds true for brightness; however, lowering brightness too much results in black crush. So, I'm wondering if lowering or increasing green cut and then compensating with the brightness control to avoid black crush or gray blacks can increase gamma in the same way lowering brightness does, except without the black crush?

(Of course, I would maintain D65 throughout the grayscale when doing all of this.)

There also exists the sub-brightness control in the SM but I don't know if that is any different from the standard brightness control in the user menu in terms of it's effect on gamma and black crush/clipping.

Yes, I know that cuts and drives are essentially RGB brightness and contrast controls but does that mean they work exactly the same way as regular brightness and contrast controls or is there at least some difference in how they operate with respect to my earlier question?

So, in short, are you saying that there is no way to raise gamma if I want to maintain a light output of 30 ftL and a brightness just high enough to avoid black crush (without any external help)?